WoW has attempted to address this question by producing 21 beers made from identical wort, fermented in identical containers at the same time, from a wide variety of ale yeasts. The wort used was Tied House amber (graciously donated by the Tied House), which is an excellent choice for this experiment--sufficient character to be in line with beers one might realistically want to produce without being overtly hoppy or dominated by any unusual malt characteristics. The yeasts used were all the Wyeast ale yeasts (except the Belgian and Weizen strains), White Labs' Burton and American Wheat (Zum Uerige/Widmer) strains, Head Start's Alt yeast, and WoW's own top secret, fast acting, high temperature-tolerant strain. Yeast was kindly donated by Wyeast and Fermentation Frenzy.
Starting on 4/7/99 fermentation was monitored by closing the safety valve for 1 hour. If the pressure built up during this time escaped in less than 2 seconds, the keg was then tested for 24 hours. If the pressure from this longer test escaped in less than 2 seconds the kegs was closed for good. Two batches were closed on the first test. The rest were finished within a week or so. Since pitching rates were not measured and were probably not similar, we don't report the finishing time for each yeast. There was no racking at any point--beer was served from the primary fermenter.
The complete transcribed tasting data are available as a 60KB Microsoft Excel 7/PC file here. Following is a summary of the responses:
|Yeast Name||Wyeast # (Unless otherwise noted)||Malt Quality||Malt Quantity||Sweetness||Ester Quality||Ester Quantity||Other Fermentation Character (solvent, phenol...)||Bitterness||Other hop comments||Other comments|
|Ale yeast blend||1087||4, thin||4||3||various fruits noted||5||a few off characters||3||thin, yeasty|
|American||1056||4, neutral||4||4||good, some fruits noted||3||a few off characters, including phenol||4||clean/neutral often noted, but a few off notes too|
|American II||1272||5, caramel||5||4||banana, other fruits noted||3||a few off characters, including phenol||4|
|American Wheat||1010||3||4||5||various fruits noted||4||phenol and sulfur often noted, other off notes too||4||wheat beer taste|
|British||1098||4||4||4||various fruits noted||4||diacetyl often noted||3||acidic|
|British II||1335||5||4||4||clean, some fruit noted||3||a few off characters||4||More aroma than most||clean/neutral often noted|
|Burton Ale||White Labs WLP023||4, neutral||4||4||4||a few off characters, including phenol/spice and sulfur||4||lower aroma than most||various negative comments|
|East Coast Ale||White Labs WLP008||3||4||3||3||5||6||4||clean/neutral, negative comments|
|Head Start Alt||4||3||2||4||sulfur often noted (5/7)||4||3||sour, infected? (one person each)|
|London||1028||6, some positive comments||5||4||5||4||diacetyl, clean||4||positive comments|
|London III||1318||5||5||5||5||4||a few off characters||4||More hop flavor/aroma than most||positive comments, [astringent/chalky (one person each)]|
|London ESB (II)||1968||6||5||5||5, melon and other fruits noted||4||clean, also a few off characters||4||a bit more than most||citrus|
|Scottish||1728||5||5||5||5||5||a few off characters||4||lower than most||citrus|
|Thames valley||1275||6||5||4||6||4||a few off characters||6||positive comments|
The general consensus was that fermentation temperature was too low for the yeast to exhibit their best performance. With the exception of a few yeasts, any esters noted here were very subdued and in any other context these beers would have been called very clean. Likewise, I feel that the occaisional mention of phenol should not be taken to indicate contamination since in every case a minority of people detected anything in this area. All comments are those of people desperately trying to find something unusual in one of a series of very plain, very similar beers.